We have a multicast server Web application that connects groups of desktop users to a support forum, similar to an instant-messaging service. Workstations that have upgraded to XP Service Pack 2 cannot connect to this service. We believe the new firewall is blocking the connection but aren’t sure how to adjust the settings for a multicast connection. Can the XP SP2 firewall be opened to allow multicast connections?
The XP SP2 firewall can be configured to permit connections to and from a multicast service.
To change the firewall settings, open the Network Connections applet in the control panel, right-click on the Local Area Connection icon and choose Properties. Click on the Advanced tab in the Properties dialog and click on the Settings button. This opens the Windows Firewall dialog.
To change the firewall configuration, uncheck the Don’t Allow Exceptions check box, click on the Exceptions tab in the Windows Firewall dialog and click the Add Program button. Choose your multicast client program from the list of programs, or browse for it using the Browse button.
Once the program has been added to the Exceptions list, you should be able to connect to your multicast server.
